The present invention relates to a surgical instrument for use in performing anterior cruciate ligament reconstruction operations. The anterior cruciate ligament (ACL) is an important ligament in the center of the knee joint. The ACL stabilizes the knee during change-of-direction activities, such as in sports like soccer and basketball, preventing abnormal movement of the joint surfaces.
A torn ACL typically cannot be repaired, i.e., it will not heal, and therefore it must be reconstructed. ACL reconstruction involves replacing of the ligament with a similarly sized piece of tissue, known as a graft. Once healed in position, the graft is intended to function like a normal ACL.
A commonly performed technique for reconstructing the ACL is the “transtibial” technique. In this technique, a bone tunnel is drilled through the tibia such that the tunnel enters the knee joint where the ACL would normally attach. A drill guide is then inserted through the drilled tunnel to position a guide wire on the femur. A cannulated reamer is used to drill a second bone tunnel on the femur. A graft is then passed through the tibial tunnel, across the joint space and into the femoral tunnel. When the graft is fixed in position, it connects the two normal attachment points of the original ACL, thereby replicating the function of a normal ACL.
Recent medical studies suggest potential problems associated with the transtibial technique. A primary problem is that the tibial tunnel prevents the surgeon from positioning the guide pin for the femoral tunnel in an anatomic position. This is related to the orientation and rigidity of the tibial tunnel. Instruments passed through the tibial tunnel generally are not able to position the femoral tunnel correctly
An alternative to the transtibial technique, is the AM portal technique. In this technique, a drill guide is passed through a small incision at the joint line, known as the anteromedial (AM) portal, rather than through the tibial tunnel. This technique allows better graft placement, but is technically much more difficult. It requires that the knee be bent much more during surgery, which decreases the surgeon's visibility, and has been associated with a higher complication rate. There are other ACL reconstruction techniques, but they are generally more cumbersome for the surgeon than the AM Portal technique.
Many practicing orthopedists were trained to perform ACL reconstructions using the transtibial technique, however, most orthopedists perform a relatively small number of ACL reconstruction surgeries each year. As such, the use of an unfamiliar and more complicated technique is less desirable among many practitioners.